Propulsion of ships.



No. 884,079. PATENT ED APR. 7, 1908.

E. J. DUFF.

PROPULSION 0F SHIPS.

APPLIGATION FILED OUT. 3, 1906.

3 SHEETS-SHBET 1.

11 Karma No. 884,079. PATENTED APR. 7, 1908. B. J. DUFF.

PROPULSION OF SHIPS.

APPLICATION FILED OGT.3, 1906.

3 SHEETS-SHEET 2.

WITNESSES 44 INVENTOR No. 884,079. PATENTED APR. 7, 1908. E. J. DUFF.

PROPULSION OF SHIPS.

APPLICATION FILED 0OT.3, 1906.

3 SHEETS-SHEET 3.

L ;Z 6 INVENTOR dMnmvL W Wm MW) EDWARD JAMES DUFF, OF LIVERPOOL, ENGLANDPROPULSION or SHIPS.

No. ss4,o79.

Specification of Letters Patent;

Patented April 7, 1908.

Application filed October'3, 1906. Serial No. 337,193.

To all whom it may concern."

Be it known that I, EDWARD JAMES DUFF,

a subject of the Kingof Great Britain and- Ireland, and a resident ofLiverpool, in the county of Lancaster, En land, have invented certainnew and usefu Improvements in Connection with the Propulsion of Ships,and

of which the following is the specification.

My invention has for its ob ect to provide improved means for thepropulsion of ships so as thereby to augment the speed hithertoobtainable when using an engine or engines of a given ower; or so as toobtain any desired spee with lighter engines thereby effecting economy,in steam and coal consumption, (when a steam engine is used) andconsequently' also saving boiler and bunker space.

According to my invention the engine, or

engines,'dr1ves a propeller shaft or shafts the passing through a tunnel'inthe ship,

aug-

tunnel being openat both ends, and

. ment the rotative effort put upon the shaft or shafts by the enginebyuti'lizlng the power which is in the head of water required to floatthe ship, the pressure water thus ob,- tained enterm one end of thetunnel and driving a turbine or turbines or equivalent motor on theshaft or shafts, or; eared thereto, or on a second propeller sha t. Thewater from the turbine is ejected from the tunnel by a second turbine, arotary pump, geared thereto, and reacts upon the depth of water to ivethe pro ulsive thrust.

It will e obvious t at in carrying out 'my invention the differentintegers may be are ranged in various ways without de arting from theessence of the invention, W 'ch is the utilization of the power. whichis in the head of water required to float the ship to augment thecapacit of a prime mover for propulsion of such s 'p; but in order thatmy invention and they manner of performing the same may be properlyunderstood I hereunto append. three sheets of explanatory drawingsshowin by way of example only, in diagrammatic orm three possible aplioations of my invention, Figures 1 and 2, Sheet 1, being, respectivela sectional side elevation and a sectiona plan of a 'portion of a shiand showing one example; while Figs. 3 an 4, Sheet, 2, and Figs. 5and/6, Sheet 3, are, res ectively, similar views showing second an thirdexamples.

In carrying out the invention accordin to the example shown in Figs. 1and 2, a prime less power be required.

mover, A, which may be an ordinary recipro eating steam engine, or othereng ne of any suitable-known construction, drives-a ropeller shaft, B,passing through a tunne C,

in the ship, the tunnel being open at both ends, the inlet to theforward open end being throu h an opening, D, (shown by dotted linesficasing of a turbine, E, or equivalent motor,

E, .is on the shaft, B, or it may be geared thereto, and to drive theturbine I utilize the power which is in the head of water required tofloat the ship, the pressure water thus obeading from the hull of theship to the tained entering the opening, D, and driving the turbine, E,thus augmenting the rotative effort put upon the shaft, B, by theengine, A. The first turbine or motor, E, which may be of any suitableknown construction, is of such capacity that it and theengi ne, A, worktogether at such a speed-that the pressure of watergives up its power inaiding the rota tive power of theengine upon the shaft, B, and pressure.The centrifugal pump, G, or second turbine which may also be of anysuitable known construction, must be capable of such a duty that thetail water leaving the first turbine, E, is removed at such a speed asprevents the possibility of pressure accumu eaves the turbinepractically without ating in the ortion of the race behind the firstturbine, an by the ejection of the water by the propellers, or the like,against the head of water in the tail end of the tunnel,-C,

. increased power is obtained towards propulsion of the ship. In otherwords, the pump G should be capable of displaying as much or a littlemore water than is admitted to the tail race by the turbine.

Owin to th augmentation of shaft torque by the first turbine or motor,the capacity of a prime mover of given power is considerabl augmentedtowards propulsion of the vesse so that with a given motive powerincreased speed may be obtained, or for a given speed The arrangementherelnbefore described.

could be fitted in duplicate to a ship, one at each side, and thus givetwin screw propuls1on;'and,1f.des1red, an ordinary screw pr0- anarrangement practically similar to the peller shaft could be arrangedbetween so as modification herembefore described, but not e5(hereinafter referred to) which 1n turncome municateswith the tunnel, C.The turbine,

requiring a se arate pro eller shaft for reversing. In tiis exam 1e, theturbine, E, on the forward end of .t e shaft, B, is of the axial flowtype, and instead ofthe rotatory pump (G) on the shaft, B, at'the exitend of the tunnel as described in the preceding example, a second axialflow turbine, M, is used. Turbines" of this type are reversible machinesand consequently when the prime mover, A,

rotates the shaft, B, so that water entering the openings, D, drives theforward turbine, E, then the rear turbine, M, will'throw out the wateito obtain the propulsive efi'ort as hereinbefore described; but when'theshaft B, is rotatedin the op osite direction for reversing, the rear turine, M, which. preturbines, E, or equivalent motors, ma used to utilizethe power which is in the cad viously threw out the'wat'er is now drivenby water then entering that endof the tunnel, -C, arid the forwardturbine, E, now acts as a propeller and throws out the water through theopenings, D.

According to the example shown in Figs. 5 and 6, the tunneL'C, isso'shaped that tvgo e of water required to float the ship, theseturbines being each on a separate shaft, H, ar-

ran ed one on each side of the ship, and each sha t havin on its outerend a'screw propeller, J. 'fhe water from the turbines, E, passes intothe central portion of the tunnel C, from which it is discharged againstthe head of water existin outside the ship, as hereinbefore describe bymeans of a rotatory pump, G, on a shaft, B, driven by a prime mover, A,of anysuitable known construction. Instead of a pump, G, asecondturbine, may be used in this example as in the examplehereinbeforedescribed with reference to Figs. 1 and 2, of theaccompanying drawings; and as the reaction ofthis Water dischargingpump,G, or the like, is

equivalent in efficiency to that of an ordinary-screw propeller, the netgain in propulsion is that given by thepressure of the sea water to thetwo outsideturbines, E.

To facilitate reversing when necessary a reversing steam turbine, K, orother suitable motor is arranged in connection with each shaft, H, sothat it may be connected to such ear-m9 shaft by any, suitable form ofclutch (not shown) when it is required to run the ship backwards; Orthese motors, K, may be permanently connected with the shafts, H,

and run idle while the turbines, E, are

working, and, of course, when the motors are working the turbines willnot. be domg .any useful work, but as reversing isonly usually requiredfor short eriods this is of little moment. It is possi le also thatinstead of using r'eversin motors, K, the shafts,

-H, might be connecte when desired for reversing purposes, to the mainengine shaft, B, by means of suitable gearing or by a belt or chaindrive. Or, as in the example hereinbefore described with reference toFigs. 3

and 4, the turbine, E, and rotatory pum ,G,

may be replaced by two axial flow tur ines so that either will act asthe turbine when the other is acting asa propeller, de ending on thedirection of rotation of the siiaft, B, andthe desired aid to propulsiveeffort wiil thus be obtained for both directions of propulsion.

It is to be understood thatalthough in the claims unities of integersare expressed, pluto float the ship is utilized, said centrifugal pumpadapted to eliminate the back pressure on the turbineand capable ofremoving more water than is admitted by the turbine.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses.

EDWARD JAMES DUFF.

Witnesses WILLIAM TowNs, RALPH GIBBs.

